In a message dated 8/29/01 8:54:01 PM Pacific Daylight Time, bjtatum@ev1.net
writes:
> I have been assembling the sections for a T-500-72 and a T-600-64 this
> week. Have been researching all over the net for installation tips, base
> preparation, etc. and have found a lot of info. It seems that most report
> erecting these towers with crane / boom trucks.
> My question is : Can anyone give me info on erecting these towers with
a
> gin pole? What type gin pole is available?
Out of the several erection techniques - using a ginpole IMO finishes
dead last. The problem is that the legs are varying sizes of 60 degree angle
legs and it's difficult to have a single leg fixture that clamps on the leg
that'll work.
OTOH you can use a 12' piece of aluminum with a pulley at the top for a
ginpole. You need a method for securing the bottom - I use an 'S' hook or
sling and carabiner. The bottom hook just sits in the junction of a leg and a
downward brace so it's secure. Then you lash the ginpole in a couple of
places on the leg. The top and bottom braces on each section should be loose
and then I use a truck tiedown ratchet on the bottom of the next section to
pull the legs in so that it'll slip into the section that it's being lowered
into.
My #1 pick for erection would be the crane/boomtruck. Lift it in several
segments and you're done. The crane can lift your mast and antennas while
he's there so after an hour or two, he's gone and you're just about done.
Installation photos are linked from our website - <A
HREF="http://www.championradio.com";>www.championradio.com</A> - to KA9FOX's
website.
My #2 technique is to erect the tower one piece at a time with 2 guys on
the tower. It doesn't take that long if you get the tower unassembled but the
factory is getting to be reluctant to do that. The problem is that each
section has to be assembled and plumbed and the factory doesn't think anyone
can do it properly.
> These are my first self-supporters as I have always had 70 to 100 foot
> #45G guyed towers. The 72 footer will be used for some stacked arrays of
> 903, 1296 and 2304 Mhz., as I can place it very near my shack. Does anyone
> see a problem with extending a high strength 2" mast about 12 to 15 feet
out
> the top of tower for these smaller antennas?
No.
> I had special, thicker plates made for the thrust bearing and rotor
> plates, plus an intermediate plate 3' down from the thrust bearing has a
> locking collar to help keep the mast vertical during antenna installation.
I
> was really shocked at the thin thrust bearing plates supplied by Trylon,
and
> I was told by the Canadian dealer that I was the first person to complain
of
> them- surely not!!
Yes - the plates are just sheet metal but if you're concerned, either
fabricating heavier duty plates or using two of them per location works.
I've put big masts and two yagi stacks on the Trylon plates and haven't
had any problems; the total weight was in the 200-250# range. The angle
brackets that the plates sit on offer a very secure mount and the area of the
plate that actually supports the mast/antennas is fairly small.
Remember that most of the wind pressure is trying to push the
mast/antennas horizontally and even a little plate has more than enough
strength to take a bunch of horizontal/lateral force.
Cheers, Steve K7LXC
Tower Tech
Champion Radio Products
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
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